Method of preventing inadvertent inflation of an inflatable prosthesis

ABSTRACT

A pump assembly for a penile implant is provided having a mechanism which prevents spontaneous inflation of the cylinders implanted within the user. The preventative mechanism uses overpressure generated by the reservoir during unintentional compression to effectively seal the pump assembly from unintended fluid flow. The prevention mechanism itself creates all necessary forces to prevent the undesired fluid flow to the cylinders. This is accomplished by incorporating appropriate mechanisms within the pump itself.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a divisional of U.S. patent application Ser. No. 10/313,251,filed on Dec. 6, 2002 now U.S. Pat. No. 6,935,847, which is a divisionalof U.S. patent application Ser. No. 09/749,256 filed Dec. 27, 2000, nowU.S. Pat. No. 6,533,719, issued Mar. 18, 2003.

BACKGROUND OF THE INVENTION

This invention generally relates to a pump for inflating a prosthesesand more particularly to a pump and valve assembly including a diaphragmwhich inhibits spontaneous inflation of the prosthesis.

One common treatment for male erectile dysfunction is the implantationof a penile prosthesis. Such a prosthesis typically includes a pair ofinflatable cylinders which are fluidly connected to a fluid reservoirvia a pump and valve assembly. The two cylinders are normally implantedinto the corpus cavernosae of the user and the reservoir is typicallyimplanted in the user's abdomen. The pump assembly is implanted in thescrotum. During use, the user actuates the pump and fluid (typicallyliquid) is transferred from the reservoir through the pump and into thecylinders. This results in the inflation of the cylinders and therebyproduces the desired penis rigidity for a normal erection. Then, whenthe user desires to deflate the cylinders, a valve assembly within thepump is actuated in a manner such that the fluid in the cylinders isreleased back into the reservoir. This deflation then returns the penisto a flaccid state.

With inflatable penile prostheses of current designs, spontaneousinflation of the cylinders is known to occasionally occur due toinadvertent compression of the reservoir. Specifically, this inadvertentcompression results in the undesired introduction of fluid into thecylinders. While this does not create a medical or physical problem,such inadvertent inflation can be uncomfortable and embarrassing for theuser. This undesirable condition is further described below withreference to a particular prosthetic design.

With reference to FIG. 1, a known pump and valve assembly 8 for use in apenile prosthesis includes a fluid input 10 that is coupled at one endto a reservoir (not shown) and to a housing 12 at its opposite end. Alsoconnected to the housing 12 is a fluid output 14 which, in turn, isconnected at its other end to a pair of cylinders (not shown). Linkingthe fluid input 10 and the fluid output 14 to each other is a commonpassageway 33, which itself contains a valve assembly that is describedin greater detail below. Common passageway 33 is also in fluidcommunication with a pump bulb 18 that is used to move fluid from thereservoir (not shown) to the cylinders (not shown) in order to inflatethe cylinders. The valve assembly located within common passageway 33includes a reservoir poppet 20 which is biased against a valve seat 24by a spring 28 and a cylinder poppet 22 which is biased against a valveseat 26 by a spring 30. The springs 28 and 30 are sized so as to keepthe reservoir poppet 20 and the cylinder poppet 22 biased against eachrespective valve seat 24 and 26 under the loads that are encounteredwhen the reservoir is pressurized to typical abdominal pressures.

When the user wishes to inflate the cylinders, pump bulb 18 is squeezedso as to force fluid from the pump bulb 18 into the common passageway33. The resulting fluid flow creates a fluid pressure on reservoirpoppet 20 which compliments the force of the spring 28 to hold thereservoir poppet 20 against valve seal 24. The fluid flow also causescompression of the spring 30, and thereby opening cylinder poppet 22. Asa result, the fluid travels out through fluid output 14 and into therespective cylinders.

When the user releases the pump bulb 18 a vacuum is created, thuspulling the poppet 22 back against valve seat 26 (aided by spring 30)and simultaneously pulling the reservoir poppet 20 away from its valveseat 24, against the spring 28. As a result, fluid from the reservoir isthus allowed to flow through the fluid input 10 to the common passageway33, passing around the reservoir poppet 20. Fluid then will freely flowinto the vacuous pump bulb 18. Once the pump bulb 18 has been filled,the negative pressure is eliminated and the reservoir poppet 20 returnsto its normal position. This pumping action of the pump bulb 18 andvalve assembly is repeated until the cylinders are fully inflated asdesired.

To deflate the cylinders, the user grips the housing 12 and compressesit along the axis of reservoir poppet 20 and cylinder poppet 22 in amanner such that the wall 13 of the housing 12 contacts the protrudingend 21 of the reservoir poppet 20 and forces the reservoir poppet 20away from valve seat 24. This movement, in turn, causes the reservoirpoppet 20 to contact cylinder poppet 22 and force cylinder poppet 22away from valve seat 26. As a result, both poppets 20 and 22 are movedaway from their valve seats 21 and 26 and fluid moves out of thecylinders, through the fluid output 14, through common passageway 33,through the fluid input 10 and back into the reservoir.

Although the springs 28 and 30 are sized to provide sufficient tensionto keep poppets 20 and 22 firmly abutted against valve seats 24 and 26under normal reservoir pressures, it is possible for fluid pressure toexceed the force provided by the springs during heightened physicalactivity or movement by the user. Specifically, this activity ormovement can apply excess pressure to the reservoir. Such excessivepressure on the reservoir may overcome the resistance of thespring-biased poppets 20 and 22 and thereby cause a spontaneousinflation of the cylinders. Encapsulation or calcification of thereservoir can sometimes occur in a patient. This encapsulation couldlead to a more snugly enclosed reservoir, thus increasing thepossibility of providing excess pressure on the reservoir and thelikelihood of spontaneous inflation.

As such, there exists a need to provide a prosthetic penile implanthaving a spontaneous inflation prevention mechanism that is reliable andeasy to operate.

BRIEF SUMMARY OF THE INVENTION

The present invention includes a penile pump having a dual poppetarrangement wherein the poppets act as check valves or flow valves. Eachpoppet is spring-biased against a valve seat, and under normalcircumstances, only allows positive fluid flow when a pump bulb isengaged. To prevent spontaneous inflation when an overpressurizationoccurs in the reservoir, the same reservoir pressure is utilized to sealthe fluid output against itself or to seal one or both of the poppetsagainst the valve seat. Thus, the fluid is prevented from reaching thecylinders and creating a spontaneous inflation. When the movement oractivity generating the overpressure in the reservoir is released, thesystem will return to an equilibrium and allow normal operation. Even ifoverpressurization of the reservoir is occurring, the pressure generatedby compressing the pump bulb will far exceed the level of overpressure.Thus, the poppets will open in the normal way, allowing fluid to flow tothe cylinders.

The use of the overpressure in the reservoir itself to prevent fluidflow to the cylinders can be accomplished in a variety of formats. Eachof these formats however, generally utilize a structure in fluidcommunication with the reservoir which is capable of restricting flowcaused by reservoir overpressurization.

In a first embodiment, a bypass passageway is provided from the fluidinput which terminates in an expansion chamber located directly behindthe cylinder poppet. A portion of the housing forms a wall between thischamber and the cylinder poppet. This wall is larger in surface areathan the surface area of the cylinder poppet exposed to theoverpressure. Since the surface area of the wall is larger than the areaof the poppet that contacts the valve seat, the same amount of pressuregenerated by the reservoir will cause a larger force to be applied bythe chamber wall against the poppet than is applied against the poppetthrough the common passageway. Thus, the cylinder poppet is effectivelysealed when an overpressurization occurs in the reservoir.

In another embodiment, the bypass passageway is similarly coupled to thefluid input, bypassing the poppets and terminating in an expansionchamber. The cylinder poppet passageway output leads into a terminationchamber connected to the expansion chamber. The expansion chamber islarger than the cylinder poppet output. Located within the expansionchamber is a flexible diaphragm dividing the chamber into two portions.As overpressurization occurs in the reservoir, this pressure is directedthrough the bypass passageway and is applied to the diaphragm. Thispressure causes the diaphragm to flex against the output of the poppetchamber, effectively sealing it. In this sealing position, the diaphragmprevents fluid from reaching the cylinders.

In yet another embodiment, a fluid bypass passageway is provided whichconnects the fluid input and a chamber which surrounds a portion ofcompressible tubing. The compressible tubing forms part of the outputthat leads from the cylinder poppet to the cylinders. Asoverpressurization occurs in the reservoir, this force is directed alongthe bypass passageway causing the flexible tubing to compress, thuseffectively sealing it off. Once again this prevents fluid flow to thecylinders because the flexible tubing is part of the output.

In a further embodiment, a fluid bypass passageway is provided betweenthe reservoir and a fluid return passageway. The fluid return passagewaycouples an expansion chamber to an intermediate chamber between thereservoir poppet and the cylinder poppet. A bypass check valve isincluded in the bypass fluid passageway and allows pressurized fluid toflow from the input chamber into the return passageway. A return checkvalve is provided within the return fluid passageway between theintermediate chamber and the point where the bypass fluid passagewayintersects the return fluid passageway.

Thus, in an overpressure situation, pressurized fluid is allow to flowfrom the input chamber through the bypass fluid passageway and into theexpansion chamber. The expansion chamber includes a flexible abuttingwall which is caused to engage the cylinder poppet and to firmly seatit. In this situation, spontaneous inflation is avoided.

While spontaneous inflation is prevented, pressurized fluid is able toenter the intermediate chamber. When the pressure of the fluid in thereservoir and the input chamber is reduced, this pressurized fluidremains in the intermediate chamber. If the expansion chamber were justallowed to relax when fluid pressure in the reservoir is reduced, it maybe possible for the pressurized fluid in the intermediate chamber toopen the cylinder poppet and partially inflate the cylinders. Thus, byproviding this configuration of a bypass fluid passageway and a returnpassageway with the appropriate check valves, the pressured fluidentering the expansion chamber will be caused to remain there until thefluid pressure in the intermediate chamber is reduced. When the pumpbulb is actuated, sufficient pressure is generated to overcome theopposing force generated in the expansion chamber and the cylinderpoppet is unseated.

In still another embodiment, a bypass fluid passageway and a returnfluid passageway are provided wherein each includes a check valve aspreviously described. However, in this embodiment, both the bypass fluidpassageway and the return fluid passageway are fluidly coupled to theinput chamber. In addition, the return fluid passageway is coupled tothe intermediate chamber. Located within the return fluid passagewaybetween the intermediate chamber and the input chamber is a fluidresistor.

When an overpressurization situation occurs, pressurized fluid willenter both the expansion chamber and the intermediate chamber. Aspreviously described, the expansion chamber will seat the cylinderpoppet firmly against the opening. As fluid pressure is reduced in thereservoir and input chamber, the fluid resistor allows pressurized fluidfrom the intermediate chamber to bleed back to the input chamber. Thus,eventually, the fluid pressure within the immediate chamber will belower than the fluid pressure within the expansion chamber. Once thisoccurs, the return check valve will open and the pressurized fluidwithin the expansion chamber can return to the input chamber. Due to theconfiguration of the return check valve and the fluid resistor, pressurelevels within the expansion chamber will always be higher than pressurelevels within the intermediate chamber and, as a result, the cylinderpoppet will always be firmly seated.

In still yet another embodiment, a bypass fluid passageway and a returnfluid passageway are provided wherein each is fluidly coupled to theinput chamber. A check valve is placed within the bypass fluidpassageway which only allows fluid to flow from the input chamber to theexpansion chamber. Located within the return channel fluid passagewayare a pair of fluid resistors placed on either side of a passageway intothe intermediate chamber. When an over-pressurization situation occurs,pressurized fluid opens the bypass check valve and allows fluid flowthrough the bypass fluid passageway to the expansion chamber. Thispressurized fluid then firmly seats the cylinder poppet. Pressurizedfluid will also enter the intermediate chamber. When pressure is reducedin the reservoir and the input chamber the pressurized fluid trappedwithin the intermediate chamber is slowly able to bleed through a singlefluid resistor into the input chamber. As fluid pressure is reduced inthe intermediate chamber and the portion of the return fluid passagewaylocated between the fluid resistors, the pressurized fluid within theexpansion chamber is slowly able to bleed through the second fluidresistor and eventually into the input chamber.

In still another embodiment a bypass fluid passageway is provided thatcouples the input chamber to an expansion chamber. The intermediatechamber is also fluidly coupled to the bypass fluid passageway. A firstfluid resistor having a relatively low fluid resistance is placedbetween the intermediate chamber and the bypass fluid passageway. Asecond fluid resistor having a higher impedance is placed between theexpansion chamber and the intermediate chamber. A bypass channel isconstructed around the second fluid resistor and includes a bypass checkvalve allowing fluid to flow from the bypass fluid passageway around thesecond fluid resistor and into the expansion chamber. When anover-pressurization situation occurs, pressurized fluid will be trappedwithin the expansion chamber and the intermediate chamber. When pressureis reduced, pressurized fluid is able to flow from the intermediatechamber through the low impedance fluid resistor through the bypassfluid passageway and into the input chamber. As pressure levels dropwithin the bypass fluid passageway pressurized fluid will eventually beable to flow from the expansion chamber through the high impedance fluidresistor and into the input chamber. This configuration also ensuresthat fluid pressure levels within the expansion chamber will always behigher than those within the intermediate chamber (except duringactuation of the pump bulb). Thus, preventing spontaneous inflation.

In another embodiment, an input chamber is provided that is connected tothe fluid input, prior to the point the fluid input engages the firstpoppet. At the output of the pump, a passageway leading from thecylinder poppet to the cylinders is caused to narrow in a throat region,which is located proximate the input chamber. When an overpressurizationof the reservoir occurs this input chamber is caused to expand, thusforcing its outer walls to move outward. Outward movement of the outerwalls effectively seals the throat portion, thus preventing fluid flowfrom the reservoir from reaching the cylinders.

In still yet another embodiment a separate problem is addressed. Namelyinadvertent compression of the valve walls may lead to an unseating ofthe reservoir and/or cylinder poppet and possibly lead to spontaneousinflation. To prevent this it may be desirable to make the housingsubstantially more rigid. This can be accomplished by encasing thereservoir and cylinder poppets within a solid cylindrical membrane.

In most of the above outlined embodiments, the force generated by anoverpressurization of the reservoir is used to prevent fluid flow intothe cylinders.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side-sectional view of a penile pump according to theteachings of the prior art.

FIG. 2 is a side-sectional view of a penile pump in a state ofequilibrium, having a termination chamber which can force the cylinderpoppet against a valve seat during an overpressurization situation.

FIG. 3 is a side-sectional view of the penile pump shown in FIG. 2during an overpressurization situation.

FIG. 4 is a side-sectional view of a penile pump having a diaphragmmember between a bypass passageway and the cylinder poppet output.

FIG. 5 is a side-sectional view of a penile pump having a diaphragmbetween the bypass passageway and the cylinder poppet output.

FIG. 6 is a side-sectional view of a penile pump having a bypasspassageway which compresses a collapsible portion of the fluid output.

FIG. 7 is a side-sectional view of a penile pump having a bypass fluidpassageway and a return fluid passageway with a check valve located ineach.

FIG. 8 is a side-sectional view of a penile pump having a bypass fluidpassageway and a return fluid passageway with a check valve located ineach and a fluid resistor located within the return fluid passageway.

FIG. 9 is a side sectional view of a penile pump having a bypass fluidpassageway and a return fluid passageway with a check valve located inthe bypass fluid passageway and a pair of fluid resistors located withinthe return fluid passageway.

FIG. 10 is a side sectional view of a penile pump having a bypass fluidpassageway with a pair of fluid resistors and a bypass channel with acheck valve.

FIG. 11 is a side-sectional view of a penile pump having a fluid outputthat has a reduced throat portion that is sealable during anoverpressurization situation.

FIG. 12 is a side sectional view of a penile pump having a rigidifyingcylindrical element located within the housing.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, a pump assembly is shown and generally referred toas 8. Pump assembly 8, as illustrated in FIG. 1, is essentially that ofthe prior art, but an understanding of the working elements of pumpassembly 8, as illustrated in FIG. 1, is beneficial to understanding theoperation of each embodiment of the present invention. Generally, thepump assembly 8 will be implanted into the user's scrotum. A separatefluid-filled reservoir (not shown) is implanted in some other portion ofthe user's body, usually in the abdomen. Fluidly connecting thereservoir to the pump assembly 8 is fluid input 10 which will usually bea flexible silicone tube. A pair of inflatable cylinders (not shown) areusually implanted in the user's corpus cavernosae and are fluidlyconnected to pump assembly 8 via fluid output 14, which is also usuallya flexible silicone tube.

In general, when pump assembly 8 is actuated, fluid is drawn from thereservoir through the pump assembly 8 and pumped into the cylinders.During the inflation process and until released by the user, the pumpassembly 8 maintains the fluid pressure in the cylinders, thus keepingthem in their inflated state. When deflation is desired, the usermanipulates assembly 8, permitting fluid to transfer out of theinflatable cylinders and into the reservoir, thereby deflating thecylinders and returning them to a flaccid state.

Pump assembly 8 generally includes a housing 12 usually formed ofsilicone. Attached to housing 12 is a pump bulb 18, which includes arelatively large pump chamber 36. Fluid input 10 is coupled to thehousing 12 and empties into an input chamber 16. As such, fluid input 10couples input chamber 16 to the reservoir. A common passageway 33 isfluidly coupled between input chamber 16 at one end of the housing 12,and fluid output 14 at an opposite end of the housing 12. Similarly, thepump chamber 36 is fluidly coupled to the common passageway 33 via pumppassageway 34.

Disposed within common passageway 33 is a reservoir poppet 20 whichfunctions as a check valve. Reservoir poppet 20 is an elongated memberhaving a contoured portion which abuts reservoir poppet valve seat 24forming a fluid tight seal. A reservoir poppet spring 28 engagesreservoir poppet 20 and biases reservoir poppet 20 against the reservoirpoppet valve seat 24. Also disposed within common passageway 33 and inline with reservoir poppet 20 is cylinder poppet 22. Cylinder poppet 22forms a second check valve within common passageway 33. Cylinder poppet22 is biased by cylinder poppet spring 30 against cylinder poppet valveseat 26 in a normal state, thereby forming another fluid tight sealwithin common passageway 33. Reservoir poppet 20 is substantially longerthan cylinder poppet 22. A front end of reservoir poppet 20 extends intoinput chamber 16, in close proximity to an outer wall of housing 12.Furthermore, the front end of cylinder poppet 22 is in close proximityto the rear end of reservoir poppet 20. As such, the user can manipulateboth poppets 20 and 22 by compressing the wall of housing 12.Compression of the housing 12 will cause the reservoir poppet 20 tocompress reservoir poppet spring 28 thus displacing the reservoir poppet20 from reservoir poppet valve seat 24. This motion will also causecylinder poppet 22 to be displaced from cylinder poppet valve seat 26while compressing cylinder poppet spring 30. When both reservoir poppet20 and cylinder poppet 22 are displaced from their respective valveseats, fluid is allowed to freely flow between input chamber 16 andfluid output 14, and hence fluid is allowed to freely flow between thereservoir and the cylinders.

During a majority of the time, pump assembly 8 will be in theconfiguration shown in FIG. 1. That is, both reservoir poppet 20 andcylinder poppet 22 are abutting their respective valve seats 24 and 26,forming a fluid tight seal. When inflation is desired, pump bulb 18 ismanually compressed by the user. This forces the fluid in pump chamber36 out through pump passageway 34 and into common passageway 33, underrelatively high pressure. Because of the location of pump passageway 34with respect to the reservoir poppet 20, this increased pressure causesreservoir poppet 20 to further abut reservoir poppet valve seat 24. Thisincreased pressure is more than sufficient to remove cylinder poppet 22from its abutment with cylinder poppet valve seat 26, by compressingcylinder poppet spring 30. As such, the pressurized fluid is allowed topass through a portion of the common passageway 33 and into fluid output14, where it eventually reaches an inflatable cylinder. When released,the pump bulb 18 expands back to its original configuration, creatingnegative pressure within pump chamber 36 and common passageway 33. Thisnegative pressure draws cylinder poppet 22 towards valve seat 26 andsimultaneously pulls reservoir poppet 20 away from valve seat 24. Assuch, fluid is drawn from the reservoir, and into pump chamber 36 untilthe negative pressure is eliminated. Then, reservoir poppet spring 28causes the reservoir poppet 20 to reseat itself against valve seat 24.

Repeated compression of pump bulb 18 eventually inflates the cylindersto a sufficient degree of rigidity for the user. Once inflated, thefluid remaining in fluid output 14 is under a relatively high degree ofpressure. This high pressure fluid aids cylinder poppet spring 30 inforcing cylinder poppet 22 against cylinder poppet valve seat 26 againforming a fluid tight seal and preventing fluid from within thecylinders from passing back through the pump assembly 8 (preventingdeflation of the cylinders).

When the user desires deflation of the cylinders, the wall of housing 13is manually compressed. This compression forces reservoir poppet 20 awayfrom reservoir poppet valve seat 24 and simultaneously causes cylinderpoppet 22 to be removed from cylinder poppet valve seat 26. Thepressurized fluid within the cylinders and fluid output 14 naturallyreturns to the reservoir via common passageway 33. Furthermore, thecylinders can be manually compressed forcing out any remaining fluid.Once the cylinders are satisfactorily emptied, the user releases thegrip on housing 12, thus allowing cylinder poppet 22 and reservoirpoppet 20 to once again abut their respective valve seats 24 and 26.

As described above, pump assembly 8 (as shown in FIG. 1) worksrelatively well under normal circumstances. However, when the usercompresses the reservoir inadvertently through bodily movement, thepressure generated may be sufficient to remove reservoir poppet 20 andcylinder poppet 22 from their respective valve seats 24 and 26, thusspontaneously inflating the cylinders. When sufficient force isgenerated against the reservoir (or a similar component) to cause thefluid pressure to exceed the resistive characteristics of poppets 20 or22 (overcome the force of reservoir poppet spring 28 and cylinder poppetspring 30), an overpressure situation has occurred. Of course, the onlyway to release this spontaneous inflation is to manually release thecheck valves.

In order to avoid spontaneous inflation, the present invention utilizesthe overpressure created by compression of the reservoir to seal off thepump assembly output 14. This solution can be accomplished by manydifferent approaches, a number of which are outlined below. It should benoted that the order in which these different embodiments are presentedshould not be interpreted to imply any significance or importance to anyone embodiment over another.

Referring to FIG. 2, a first embodiment of the present invention isshown and described. In summary, an overpressure tolerant pump assembly9 is provided and including a bypass passageway 38 is added to thesystem which couples input chamber 16 to an expansion chamber 40. Theexpansion chamber 40 is provided adjacent to the rear end 44 of cylinderpoppet 22. The relatively thin portion of housing 12 that exists betweencommon passageway 33 and expansion chamber 40 forms an abutting wall 42.Abutting wall 42 is relatively flexible and operates very similarly to aflexible diaphragm. Importantly, the planar surface area of abuttingwall 42 is greater than the area of nose 46 of cylinder poppet 22(wherein the nose 46 is that portion of cylinder poppet 22 that would beexposed to overpressure generated by the reservoir when the cylinderpoppet 22 is seated against the valve seat 26). This “nose” area isapproximately equal to the cross sectional area of the common passageway33, at a point between the nose 46 and the rear end portion 47 ofreservoir poppet 20.

As is shown, expansion chamber 40 forms a closed chamber which has nooutput. Cylinder poppet output 32 is separate from expansion chamber 40and couples the common passageway 33 to fluid output 14.

Under normal operation, reservoir poppet 20 and cylinder poppet 22 willfunction in exactly the same manner as described above with reference toFIG. 1. When an overpressure situation occurs within the reservoir pumpassembly, the present invention will appropriately deal with thesepressures to avoid spontaneous inflation. When the reservoir is somehowcompressed by the user, pressurized fluid is directed through fluidinput 10 and into input chamber 16 (pressure is simply increased whenfluid is already present). The pressurized fluid will likewise flow into(or increase pressure within) bypass passageway 38 and fill expansionchamber 40. As pressure from the reservoir is increased, expansionchamber 40 is forced to expand, causing abutting wall 42 to pressagainst rear end 44 of cylinder poppet 22, thus achieving theconfiguration shown in FIG. 3.

Referring now to FIG. 3, abutting wall 42 forces cylinder poppet 22against valve seat 26 preventing any fluid from entering the fluidoutput 14 and inflating the cylinders. Even as the overpressuregenerated by the reservoir is sufficient to remove reservoir poppet 20from its valve seat 24, it will typically not be sufficient to removecylinder poppet 22 from its valve seat 26 because the surface area ofthe abutting wall 42 (on the expansion chamber 40 side) is larger thanthe surface area of the nose 46 of cylinder poppet 22. With equal fluidpressure being generated against both the cylinder poppet 22 and theabutting wall 42, more force will be generated by the abutting wall 42since it has a larger exposed surface area. As such, the overpressure isused against itself to prevent the cylinder poppet 22 from opening andspontaneously inflating the cylinders.

The movement of the expansion chamber 40 causing the abutting wall 42 toengage the cylinder poppet 22 will not prevent the user fromsubsequently manually inflating the cylinders. Namely, when pump bulb 18is compressed, the force generated by the compression of the fluidthrough pump passageway 34 will be many times greater than anyoverpressure generated by the reservoir. To date, it has been verydifficult to monitor and determine the pressures generated in anoverpressure situation since each user exhibits unique individualcharacteristics. Furthermore, each spontaneous inflation may result froma very different physical act on the part of the user. Pressuregenerated by compression of the reservoir is believed to result in afluid pressure of up to about 3 pounds per square inch but may be ashigh as 6-8 pounds per square inch. Conversely, compression of the pumpbulb 18 will usually generate pressures on the order of 20 pounds persquare inch. Clearly, the pressure generated by compression of the pumpbulb 18 is sufficient to overcome the force generated by abutting wall42, and allow fluid to move into the cylinders via fluid output 14.During a subsequent decompression of pump bulb 18, reservoir poppet 20will be pulled away from its valve seat 24 and fluid will be drawn frombypass passageway 38 and fluid input 10 into pump chamber 36. Thusallowing the termination chamber 40 to return to its original state.

Referring to FIG. 4, a second embodiment of the present invention isillustrated. Once again a bypass passageway 38 is provided. Bypasspassageway 38 is fluidly coupled at one end to the input chamber 16. Anexpansion chamber 49 and a junction chamber 48 are provided at theopposite end of bypass passageway 38. Cylinder poppet output 32 (whichis coupled with common passageway 33) is fluidly coupled to junctionchamber 48. Finally, fluid output 14 is also fluidly coupled to junctionchamber 48. Disposed between junction chamber 48 and expansion chamber49 is a flexible diaphragm 50. During normal operation, flexiblediaphragm is in the state represented by dashed lines. That is, flexiblediaphragm 50 is flush against bypass passageway 38. When manuallyactuated, the pressurized fluid from the pump bulb 18 is forced throughcommon passageway 33, bypassing cylinder poppet 22 and exiting throughcylinder poppet output 32 into fluid output 14, unhindered by flexiblediaphragm 50.

During an overpressure situation, the compressed fluid is forced fromthe reservoir through fluid input 10 and into input chamber 16. Frominput chamber 16, the pressurized fluid travels through bypasspassageway 38 and into expansion chamber 49. The pressure generated willcause the flexible diaphragm 50 to flex to the position represented bysolid lines. In this position, cylinder poppet output 32 is sealed.Thus, even if the overpressure is sufficient to dislodge the reservoirpoppet 20 and the cylinder poppet 22 from their respective valve seats,fluid is prevented from entering fluid output 14 and spontaneouslyinflating the cylinders.

Once again, the overpressure of the fluid is used against itself toprevent fluid from entering the fluid output 14. As is illustrated,expansion chamber 49 is relatively large compared to cylinder poppetoutput 32. More specifically, once the flexible diaphragm 50 is in theposition represented by solid lines, a larger surface area of theflexible diaphragm 50 will then be exposed to the expansion chamber 49than is exposed to the cylinder poppet output 32. As such, with equalfluid pressure being generated in the bypass passageway 38, and thecylinder poppet output 32, a greater force will be exerted in thedirection forcing flexible diaphragm 50 against cylinder poppet outlet32, due to the relative surface area ratios. When the user wishes tomanually inflate the cylinder, a compression of the pump bulb 18 willgenerate force in excess of that exerted on flexible diaphragm 50through bypass passageway 38.

FIG. 5 illustrates a variation of the embodiment illustrated in FIG. 4.Here the flexible diaphragm 50 flexes between sealing the bypasspassageway 38 and sealing the fluid output 14. Sealing the fluid output14 effectively prevents fluid from exiting cylinder poppet output 32 andentering fluid output 14. Once again it is the amount of fluid surfacearea within expansion chamber 49 that is in contact with flexiblediaphragm 50 versus the amount of fluid surface area in and aroundjunction chamber 48 (also in contact with flexible diaphragm 50) thatresults in a sufficient force differential to seal fluid output 14.

In both the embodiments shown in FIGS. 4 and 5, it should be noted thatif pressurized fluid were to exit out through cylinder poppet output 32and thus exert a force against flexible diaphragm 50 before sufficientforce was generated through bypass passageway 38, the sealing effects offlexible diaphragm 50 would effectively be bypassed and spontaneousinflation could occur. However, as is readily apparent from theillustrations, this will not happen. As overpressurization occurs in thereservoir, pressurized fluid is directed through fluid input 10 and intoinput chamber 16. The path of least resistance will be through bypasspassageway 38 rather than displacing reservoir poppet 20 and cylinderpoppet 22 from their respective valve seats. As such, flexible diaphragm50 will always be flexed to its sealing position when an overpressuresituation occurs, and this displacement will occur before either poppet20 or 22 is displaced allowing fluid to flow through cylinder poppetoutput 32.

Referring to FIG. 6, a third embodiment of the present invention isillustrated. Bypass passageway 38 fluidly couples input chamber 16 to acompression chamber 52. Compression chamber 52 surrounds a portion offluid output 14. If not already sufficiently flexible, the portion ofthe fluid output 14 within compression chamber 52 can be formed from aflexible, easily compressible material. During an overpressuresituation, compressed fluid from the reservoir is forced through fluidinput 10 and into input chamber 16. The compressed fluid flows throughbypass passageway 38 and into compression chamber 52 where it compressescompressible tube 54 (which is that section of fluid output 14 withincompression chamber 52). The amount of surface area on the outer surfaceof compressible tube 54 will necessarily be greater than the surfacearea within the compressible tube 54. As such, the force generated willbe greater in a direction compressing compressible tube 54 than acounterforce trying to expand it. As such, when an overpressuresituation occurs, compressible tube 54 is collapsed, sealing fluidoutput 14 from the cylinders and preventing spontaneous inflation.

FIG. 7 illustrates a fourth embodiment of the present invention. Thisembodiment has several elements that are in common with the previouslydescribed embodiments. Namely input chamber 16 is fluidly coupled tofluid output 14 via common passageway 33. Common passageway 33 isimpeded by a reservoir poppet 20 and cylinder poppet 22 which are bothspring biased to seat against their respective openings. The areabetween the nose of cylinder poppet 22 and the rear portion of reservoirpoppet 20 is referred to as intermediate chamber 62.

The intermediate chamber 62 is fluidly coupled to a return channel 65which is in fluid communication with expansion chamber 40. A returncheck valve 75 is provided within return channel 65 and only allowsfluid flow from expansion chamber 40 to intermediate chamber 62. Abypass channel 60 is provided and fluidly couples input chamber 16 toreturn channel 65. As indicated the junction between the bypass channel60 and return channel 65 occurs between expansion chamber 40 and returncheck valve 75. A bypass check valve 70 is provided within bypasschannel 60 and only allows fluid flow in the direction from inputchamber 16 to expansion chamber 40.

When an over-pressurization situation occurs, fluid pressure withininput chamber 16 increases. This higher pressure fluid travels throughbypass channel 60 and unseats bypass check valve 70. From here thepressurized fluid flows into the return channel 65 and into expansionchamber 40 or alternatively it unseats return check valve 75 and entersintermediate chamber 62. As fluid pressure is increased abutting wall 42is caused to deflect due to the expansion of expansion chamber 40 andfirmly abuts cylinder poppet 22 causing it to form a tight seal.Similarly fluid pressure levels within intermediate chamber 62 canincrease, however, as previously discussed due to the differences inrelative surface area the force exerted within expansion chamber 40against abutting wall 42 will always be greater than that exertedagainst the nose of cylinder poppet 22, thus preventing spontaneousinflation.

As fluid pressures within input chamber 16 decrease the elevated fluidpressure level within intermediate chamber 62 cause reservoir poppet 20to firmly seal and also cause return check valve 75 to firmly seal.(Assuming equal pressure within expansion chamber 40 and intermediatechamber 62). Bypass check valve 70 is also likewise sealed. Thus, thehigher pressure fluid within expansion chamber 40 is effectively trappedand cannot exit unless the fluid pressure levels within intermediatechamber 62 are reduced which would allow return check valve 75 to open.In other words, fluid pressures within expansion chamber 40 will alwaysbe greater or equal to the fluid pressure levels within intermediatechamber 62.

With this embodiment fluid pressure levels within intermediate chamber62 are only reduced when pump bulb 18 is actuated forcing cylinderpoppet 22 to unseat itself and causing the cylinders to be inflated.Alternatively, housing 12 could be engaged in the manner described aboveto deflate the cylinders. That is manually actuating reservoir poppet 20to disengage cylinder poppet 22. The release of reservoir poppet 20would allow pressurized fluid within intermediate chamber 62 to reenterinput chamber 16.

As fluid pressure levels within input chamber 16 increase the forcesgenerated could either unseat reservoir poppet 20, thus allowing entryinto intermediate chamber 62 or they could unseat bypass check valve 70,allowing fluid communication with expansion chamber 40. It is desirableto have fluid communication with expansion chamber 40 prior to fluidcommunication with intermediate chamber 62. Thus bypass check valve 70is configured to open at lower pressures than reservoir poppet 20. Asfluid pressures increase within input chamber 16 fluid will follow thepath of least resistance, thus opening bypass check valve 70.Subsequently pressures may be sufficient to also open reservoir poppet20, but the system will continue to work properly inasmuch as expansionchamber 40 is already expanding.

A fifth embodiment of the present invention is illustrated in FIG. 8. Areturn channel 65 is provided which fluidly couples input chamber 16 toexpansion chamber 40. Intermediate chamber 62 is fluidly coupled toreturn channel 65 via intermediate chamber passageway 64. Located withinreturn channel 65 are a return check valve 75 and a fluid resistor 80.Return check valve 75 is positioned between intermediate chamberpassageway 64 and expansion chamber 40 while fluid resistor 80 ispositioned between intermediate chamber passageway 64 and input chamber16. Bypass channel 60 is provided and fluidly couples input chamber 16with return channel 65 wherein the junction between bypass channel 60and return channel 65 occurs between the return check valve 75 andexpansion chamber 40. Located within bypass channel 60 is a bypass checkvalve 70 that only allows fluid flow in the direction from input chamber16 to expansion chamber 40. Return check valve 75 allows fluid flow fromthe direction of expansion chamber 40 towards both intermediate chamber62 and input chamber 16.

As fluid pressures within input chamber 16 increase bypass check valve70 is caused to be unseated allowing fluid flow into expansion chamber40 as previously described. The cracking pressure required to unseatbypass check valve 70 is lower than that required to unseat reservoirpoppet 20. Thus, pressurized fluid is caused to flow from input chamber16 through bypass channel 60 and into expansion chamber 40, and ifsufficient pressures are reached return check valve 75 can be unseatedand pressurized fluid can enter intermediate chamber 62. Once again aspressure levels within expansion chamber 40 increase, abutting wall 42is caused to deflect which in turn causes cylinder poppet 22 to firmlyseal preventing spontaneous inflation.

As illustrated, input chamber 16 is in fluid communication with returnchannel 65. However, fluid resistor 80 is positioned between inputchamber 16 and intermediate chamber 62. Fluid resistor 80 is a narrowingof a fluid passageway restricting fluid flow, a lengthening of the fluidpath, or a combination of the two. Fluid resistor 80 could be a separatecomponent added to the structure, rather than a modification of theexisting passageway. Thus, during an over-pressurization situation fluidflow from input chamber 16 into intermediate chamber 62 through fluidresistor 80 is trivial. Conversely, during a compression of pump bulb18, fluid resistor 80 will allow a small amount of bleed through intoinput chamber 16. This has a very negligible effect on pumping. Asdescribed with reference to the fourth embodiment, pressure levelswithin expansion chamber 40 and intermediate chamber 62 can each reachrelatively high levels. Return check valve 75 will only allowpressurized fluid within expansion chamber 40 to exit when pressurelevels within intermediate chamber 62 and the corresponding portion ofreturn channel 65 are lower than that within expansion chamber 40. Toallow this to occur fluid resistor 80 slowly allows pressurized fluidwithin intermediate chamber 62 to bleed back into input chamber 16. Overtime pressure levels within intermediate chamber 62 and input chamber 16will reach stasis. As pressure levels within intermediate chamber 62 arereduced, higher pressure fluid from expansion chamber 40 will unseatreturn check valve 75 and also eventually pass through fluid resistor 80back into input chamber 16 returning the entire system to equilibrium.

A sixth embodiment is shown with reference to FIG. 9. A return channel65 is provided and fluidly couples input chamber 16 to expansion chamber40. Intermediate chamber 62 is also fluidly coupled to return channel 65via intermediate chamber passageway 64. Located between input chamber 16and intermediate chamber passageway 64 is a reservoir side fluidresistor 90. Located between intermediate chamber passageway 64 andexpansion chamber 40 is a cylinder side fluid resistor 85. Bypasschannel 60 is provided and fluidly couples input chamber 16 to expansionchamber 40, effectively bypassing both fluid resistors 85 and 90. Bypasscheck valve 70 is provided within bypass channel 60 and allows fluidflow in the direction from input chamber 16 to expansion chamber 40.

As an over-pressurization situation occurs, pressurized fluid from inputchamber 16 flows through bypass channel 60 and unseats bypass checkvalve 70 allowing fluid entry into expansion chamber 40. Pressurizedfluid causes abutting wall 42 to deflect, thus sealing cylinder poppet22 and preventing spontaneous inflation. Bypass check valve 70 has alower cracking pressure than reservoir poppet 20 encouraging fluid flowthrough bypass channel 60 and into expansion chamber 40 prior tounseating reservoir poppet 20 and allowing pressurized fluid to flowinto intermediate chamber 62. While return channel 65 is in fluidcommunication with both intermediate chamber 62 and expansion chamber40, initially pressurized fluid from reservoir 16 will not quickly entereither of these two areas through return channel 65 due to restrictedfluid flow through cylinder side fluid resistor 85 and reservoir sidefluid resistor 90.

Once fluid pressure levels within input chamber 16 are reduced, highpressure fluids within intermediate chamber 62 will slowly bleed throughreservoir side resistor 90 and into input chamber 16. As this occursfluid pressure levels within return channel 65 will slowly decrease.When fluid pressure levels within return channel 65 on the input chamberside of cylinder side fluid resistor 85 are lower than that withinexpansion chamber 40, pressurized fluid will slowly bleed throughcylinder side resistor 85 and eventually return to input chamber 16.Once again this system always maintains a higher pressure level withinexpansion chamber 40 than is maintained in intermediate chamber 62. Justas with the previous embodiment, there will be a small amount ofpressure bleed through reservoir side resistor 90 into input chamber 16.This will have a negligible effect on pumping.

Referring to FIG. 10, a seventh embodiment to the present invention isillustrated. A bypass fluid passageway 38 fluidly couples input chamber16 to expansion chamber 40. Located within bypass passageway 38 is ahigh impedance fluid resistor 95. Intermediate chamber passageway 64fluidly couples intermediate chamber 62 to bypass passageway 38. Locatedwithin intermediate chamber passageway 64 is a low impedance fluidresistor 100. It is to be understood that with reference to fluidresistors 95 and 100 the terms high and low are with respect to oneanother. That is fluid resistor 100 has a lower fluid impedance thanfluid resistor 95. In other words, a higher volume of fluid will travelthrough low impedance resistor 100 than through high impedance resistor95 in the same amount of time when under the same pressure. Bypasschannel 60 is provided and is coupled to bypass passageway 38,effectively bypassing the high impedance fluid resistor 95. Bypass checkvalve 70 is located within bypass channel 60 and only allows fluid flowin the direction from the input chamber 16 to expansion chamber 40. Thecracking pressure of bypass check valve 70 is set such that when anover-pressurization situation occurs the path of least resistance frominput chamber 16 is to enter bypass passageway 38, open bypass checkvalve 70, and enter expansion chamber 40. Pressurized fluid mayeventually be able to unseat reservoir poppet 20 or flow through lowimpedance resistor 100 and enter intermediate chamber 62. However, theabutting wall 42 is displaced by the movement of expansion chamber 40under increased fluid pressures causing cylinder poppet 22 to sealtightly preventing spontaneous inflation.

When fluid pressures are reduced in input chamber 16 high pressure fluidcontained within intermediate chamber 62 passes more quickly through lowimpedance resistor 100 than would pass through high impedance resistor95. Hence, intermediate chamber 62 empties at a faster rate. Inaddition, fluid will only travel from expansion chamber 40 through highimpedance resistor 95 when fluid pressure levels within bypasspassageway 38 adjacent input chamber 16 are sufficiently low. That is,lower than that within expansion chamber 40. This fact coupled with theability of the intermediate chamber 62 to reduce pressure levels morequickly will always assure that pressure levels within expansion chamber40 are higher than that within intermediate chamber 62 once againpreventing spontaneous inflation. During pumping, a small amount ofpressurized fluid will pass through low impedance resistor 100, howeverthe effect will be negligible.

FIG. 11 represents an eighth embodiment of the present invention. Asillustrated, housing 12 has been slightly modified to accommodate avariety of additional internal passageways. Fluid input 10 is coupledwith a reservoir at one end and reservoir chamber 16 at the other.Located within housing 12, and coupled to fluid input 10 prior toreservoir chamber 16, is an overpressure chamber 156. Optionally,overpressure chamber 156 has an overpressure chamber input 158 having anarrowed opening. Cylinder poppet output 32 leads into an outputpassageway 160. Output passageway 160 leads to a first output chamber162 and a second output chamber 164 (actually two parts of a singlechamber or passage way). The fluid output 14 is fluidly coupled to thefirst output chamber 162. Interconnecting the output passageway 160 tothe first output chamber 162 is a relatively narrow throat portion 166.The first output chamber 162 and the second output chamber 164 arelocated proximate the overpressure chamber 156 within housing 12.Separating first output chamber 162 and second output chamber 164 is acompression wall 167 with a sealing extension 168 which also forms aportion of the narrow throat portion 166. During an overpressuresituation, fluid pressure is increased in overpressure chamber 156, thuscausing it to expand. The expansion of overpressure chamber 156 causesthe compression wall 167 and sealing extension 168 to move, thussealingly abutting throat 166 and effectively preventing fluid fromflowing through output passageway 160. Preferably, compression wall 167is configured so that a maximum amount of movement results from theforce generated, thus effectively sealing throat 166.

Referring to FIG. 12 a ninth embodiment to the present invention isillustrated. This embodiment can be used as shown or can be coupled withany of the previously described embodiments. Generally the housing 12 ofthe valve assembly will be made of a flexible material such as silicone.As such if external pressures are applied to housing 12 in an undesiredmanner, it may be possible to unseat poppets 20, 22 which may lead tospontaneous inflation. To prevent an inadvertent compression of housing12 from causing spontaneous inflation, a rigid insert is incorporatedinto housing 12 to eliminate this degree of flexibility.

As shown in FIG. 12 a solid cylindrical element 105 is incorporatedwithin housing 12 and surrounds reservoir poppet 20 and cylinder poppet22. Thus, inadvertent compression of housing 12 will be unable todisplace reservoir poppet 20 or cylinder poppet 22. Of course, tofunction properly the user must be able to manually displace reservoirpoppet 20 by compressing the side walls of housing 12, and this functionis maintained.

Since the housing 12 for the valve assembly is generally molded, it maybe desirable to have cylindrical element 105 in place during thefabrication process by including a plurality of holes 110 in cylindricalelement 105 and placing cylindrical element 105 in the mold duringfabrication. Cylindrical element 105 will in effect be molded in placeand holes 110 allow the material being utilized (i.e. silicone) to flowthrough cylindrical element 105 and properly define housing 12. Whileshown as being cylindrical, element 105 can be formed into anyappropriate shape for the valve assembly being utilized.

In general the present invention utilizes an outlet sealing mechanismthat relies on the overpressure generated by a compression of thereservoir (or similar component) to also seal the output. That is, theoverpressure generated is effectively used against itself to preventfluid from entering the cylinder and producing a spontaneous inflation.While various embodiments have been shown and described which utilizethis effect, it is to be understood that any such utilization of theoverpressure to prevent fluid flow to the cylinders is within the scopeand spirit of the present invention, and as such, the present inventionis not intended to be limited only to those specific embodiments shownand described herein.

While the present invention has been described with respect to a pumpand valve assembly for a penile implant, the use of generatedoverpressure to seal a fluid aperture has many other applications withinthe scope and spirit of the present invention. For example, artificialsphincters utilize fluid pressure to maintain a body cavity or naturalpassageway in a closed or sealed state. When actuated, fluid pressure isreleased from the sphincter, causing the bodies' passageway to open. Assuch, the fluid pressure generated could be used to assist theartificial sphincter in either state. Likewise, many other uses for anoverpressure seal exist, both specifically within the field of medicaldevices and within the field of fluid/gas handling devices in general.

Those skilled in the art will further appreciate that the presentinvention may be embodied in other specific forms without departing fromthe spirit or central attributes thereof. In that the foregoingdescription of the present invention discloses only exemplaryembodiments thereof, it is to be understood that other variations arecontemplated as being within the scope of the present invention.Accordingly, the present invention is not limited in the particularembodiments which have been described in detail therein. Rather,reference should be made to the appended claims as indicative of thescope and content of the present invention.

1. A method of preventing inflation of an implantable prostheticcomprising the steps of: biasing a valve assembly such that an outlet issubstantially closed; using pressure increases from the inlet tosupplement the biasing of the valve assembly and to prevent fluid flowthrough the outlet by selectively varying fluid pressure within a bypasspassageway having a first end which is in fluid communication with aninlet and a second end which is in fluid communication with a chamber;and displacing a flexible abutting wall disposed between the chamber andthe valve assembly so that the abutting wall is caused to contact thevalve assembly and urge the valve assembly into a closed position whenthe fluid pressure within the chamber exceeds a predetermined amount. 2.A method of preventing inflation of an implantable prosthetic comprisingthe steps of: biasing a valve assembly such that an outlet issubstantially closed; using pressure increases from the inlet tosupplement the biasing of the valve assembly and to prevent fluid flowthrough the outlet by selectively varying fluid pressure within a bypasspassageway having a first end which is in fluid communication with aninlet and a second end which is in fluid communication with a chamber;and deflecting a diaphragm located within the chamber, the chamber beingin fluid communication with the inlet and the outlet so that when thediaphragm is in a first position, fluid is able to flow from the inletand through the outlet, and when the diaphragm is in a second position,no fluid is allowed to flow through the outlet.
 3. A method ofpreventing inadvertent inflation of an implantable prosthetic comprisingthe steps of: biasing a first valve assembly in a fluid passagewaybetween an inlet and an outlet such that the outlet is substantiallyclosed; biasing a second valve assembly in the fluid passageway suchthat the fluid passageway is substantially closed to the inlet, whereinthe first valve assembly and the second valve assembly define anintermediate chamber therebetween; and using pressure increases from aninlet to supplement the biasing of the first valve assembly bypreventing fluid flow through the outlet by selectively varying fluidpressure within an expansion chamber which is in fluid communicationwith the inlet.
 4. The method of claim 3, wherein using pressure furthercomprises the steps of: displacing a flexible abutting wall disposedbetween the expansion chamber and the first valve assembly so that theabutting wall is caused to contact the first valve assembly and urge thefirst valve assembly into a closed position when the fluid pressurewithin the expansion chamber exceeds a predetermined amount.
 5. Themethod of claim 4, further comprising: preventing fluid flow out of theexpansion chamber once the inadvertent pressure increase has beenreduced until a pressure of the fluid within the intermediate chamber islower than a pressure of the fluid within the expansion chamber.
 6. Themethod of claim 4 where preventing fluid flow is accomplished using atleast one check valve.
 7. The method of claim 4 where preventing fluidflow is accomplished using at least one fluid resistor.
 8. The method ofclaim 4 where preventing fluid flow is accomplished using at least onecheck valve and at least one fluid resistor.